Don't leave the job erin. Getting job is tough these days, however , having extra credentials is always better than having none, that too from duke , you have high chance of high profile networking. These school are the hub where great thinker come for talent hunt not just for study. Study , textbooks all are same everywhere, but networking, getting guided from think tank is other.

regarding  your wife getting working full time, i didnt understand what todo mean, do you mean to say she gonna support you and be bread and butter during school days. Its noraml for nepali guys...